1. Field of the Invention
This invention relates to surgical procedures for placement and positioning of surgical instruments into the abdominal cavity of a patient for the purpose of performing laparoscopic surgical techniques. More specifically, this invention relates to the insertion of insufflation needles and cannulas into the peritoneal cavity of a patient for the purpose of performing laparoscopic surgery.
2. Statement of the Art
Laparoscopy is a surgical technique which has been known in some form for more than seventy years. Laparoscopy is generally a technique whereby the interior of the body may be viewed by means of a scope or other camera-like equipment. In its infancy, laparoscopy was used to map and catalog the pathology of the urinary bladder. Beginning in the latter part of this century, laparoscopy gained significant acceptance as a tool for performing gynecological procedures. It has only been in the past few years, however, that laparoscopy has been adapted for use in other surgical techniques relating to the abdominal region. For example, laparoscopy is now being used for intraperitoneal exploration under conditions which once required more invasive techniques. Laparoscopy is also used now to perform biopsies and necessary surgeries. The use of laparoscopy in other medical procedures is likely to increase in the future as the technique becomes more widely known and used.
Laparoscopy has recently been highlighted as a new means for conducting cholecystectomy. Previously, cholecystectomy surgery required the making of a sizable incision in the abdominal wall, between the costal margin and umbilicus, in order to access the gall bladder. Due to the severity of this surgery, a cholecystectomy patient was typically hospitalized for several days, and recovery was lengthy. With laparoscopic techniques, however, approximately one half of all cholecystectomy patients can be treated under outpatient conditions. Most patients can return to normal activity within a day or two after surgery and are limited only by any abdominal tenderness that may be experienced.
Cholecystectomy by laparoscopy is performed through at least two, and most often four, small incisions made in the abdominal region between the costal margin and umbilicus. Optical equipment and surgical instruments are inserted through the small incisions in order to perform the cholecystectomy.
Laparoscopic surgery is begun by preparing the patient for surgery following techniques well known in the art. The patient is typically given a local anesthetic in the region of the umbilicus to deaden the pain of the incisions. A pneumoperitoneum is created in order to facilitate viewing of and access to the organs. A pneumoperitoneum involves introducing a gas into the peritoneal cavity by a procedure known as insufflation.
Standard insufflation technique involves making a small (approximately 1 centimeter) incision through the dermis of the abdominal wall in close proximity to the umbilicus. The umbilical region presents the best point of entry into the peritoneal cavity because the anterior abdominal wall is thinnest at that point; however, the underlying fascia and peritoneum in the area are tough elastic connective tissues and are very difficult to breach. An apertured needle is then inserted into the incision site. A needle well-known in the art and one which is used widely for the creation of the pneumoperitoneum is the Veress needle.
A Veress needle comprises a two millimeter hollow bore needle with an apertured blunt stylet slidably disposed within the needle. The blunt stylet is spring loaded such that once the Veress needle has penetrated the tough fascial layer of the abdomen, the spring-loaded blunt stylet pops out from within the hollow needle, and an audible click can be heard. The blunt stylet extends beyond the sharp tip of the needle thus ostensibly protecting internal organs from being stabbed by the needle tip.
Correct placement of the needle can be verified by a number of different means. For example, a syringe of saline can be attached to the Veress needle, which has a luer lock at one end, and a small amount of the saline can be injected into the peritoneum. Fluid is then aspirated back out of the peritoneum. If blood is aspirated, it suggests misplacement of the needle and probable damage to an organ or vessel. The Veress needle is usually withdrawn and repositioned, followed thereafter by further testing to assure proper placement. Aspiration of yellowish fluid indicates penetration of the bowel. Again, the Veress needle must be withdrawn and repositioned. If difficult injection of saline followed by little or no aspiration is encountered, the result suggests that the needle is embedded within omentum. Aspiration of clear saline indicates a correct placement within the peritoneal cavity.
After correct placement of the Veress needle has been assured, an insufflator machine is connected to the luer lock of the Veress needle and gas is pumped into the peritoneal cavity. The Veress needle is then withdrawn from the peritoneal cavity. A cannula is inserted into the peritoneal cavity, either through another incision or through the same incision used to create the pneumoperitoneum. The cannula is placed in order to accommodate the insertion of optical and other equipment therethrough.
When using the incision through which the insufflation needle was placed, the incision must be enlarged with a scalpel to accommodate a 5 mm to 11 mm trocar. Trocars used for this procedure typically comprise a hollow-bore cannula with a sharp, pointed stylet slidably disposed therewithin. The tip of the stylet may be either a multi-faceted bevel or conical shape. The tip of the trocar is inserted into the now enlarged incision, and is forced through the underlying fascial layer and peritoneum of the abdomen using a downward pressure and drilling motion. The connective tissue of the fascia and peritoneum underlying the abdominal wall is so tough that a significant amount of force must be applied in order to achieve penetration of the tissue.
Unlike a Veress needle, trocars used in this procedure typically are not designed to shield the tip of the stylet once the stylet has penetrated the peritoneum. As a result of the intense drilling motion required to penetrate the peritoneum, the stylet can inadvertently puncture an organ or vessel upon entering the peritoneal cavity. Ethicon Company manufactures a disposable trocar with a plastic shield which covers the exposed tip of the stylet once the stylet has penetrated the peritoneum. Another frequently encountered problem of inserting a trocar through the tough fascial layer is that the elastic fascia may only stretch, similar to the head of a drum, and may resist penetration.
After the trocar has penetrated the peritoneum, the stylet is removed. The laparoscope is then inserted through the cannula portion of the trocar which remains in the abdominal wall and the peritoneal cavity is visualized. Auxiliary cannulas are positioned in other areas of the abdomen following the initial cannula placement. Positioning of the auxiliary cannulas relative to the abdominal region depends on many factors of pathology and morphology, and is assessed by viewing the peritoneal cavity through the laparoscope. Typically, auxiliary cannulas are placed in the area of the costal margin, and as such, care must be taken not to damage the epigastric vessels when placing the trocars. The auxiliary cannulas are used for insertion of surgical equipment.
The gallbladder can be visualized by the laparoscope placed through the first cannula and manipulated by the surgical instruments placed through the auxiliary cannulas. The gallbladder is excised from its position proximate the liver and is removed through the cannula inserted at the umbilicus. Each cannula is removed from its respective incision site, the peritoneal cavity is desufflated, and the incisions are sutured. The above-described techniques of laparoscopic cholecystectomy are well-known in the art and are more fully described in Berci, G. & Cuschierei, A., Practical Laparoscopy, Bailliere Tindall, 1986, p. 1-93; and Laparoscopy For the General Surgeon-Laparoscopic Cholecystectomy and Appendectomy, Karl Storz GmbH & Co., 1990.
From the above description, it can be appreciated that the method presently used for placing the insufflation equipment and for placing the trocars, or cannulas, into the peritoneal cavity presents a great deal of risk from inadvertent puncture to internal organs or vessels.